Files
libcrypto/src/secret-wrap.ts
T

99 lines
2.5 KiB
TypeScript

import logger from 'log'
import {a2b64, b642a} from 'misc'
const log = logger('crypto:secret-wrap')
export class SecretWrap {
constructor(
private readonly cipher: Uint8Array,
private readonly algorithm: KeyAlgorithm,
private readonly usages: KeyUsage[],
private readonly type: 'raw' | 'pkcs8',
private readonly iv: Uint8Array
) {}
public static gen_key(extractable: boolean = true): Promise<CryptoKey> {
log.trace('generate key')
return crypto.subtle.generateKey(
{
name: 'AES-GCM',
length: 256
},
extractable,
['wrapKey', 'unwrapKey']
)
}
private static format(type: KeyType): 'raw' | 'pkcs8' {
switch (type) {
case 'private':
return 'pkcs8'
case 'secret':
return 'raw'
default:
throw "Don't wrap public keys please..."
}
}
public static async encrypt(data: CryptoKey, key: CryptoKey): Promise<SecretWrap> {
log.trace('encrypt')
const format = this.format(data.type)
const iv = crypto.getRandomValues(new Uint8Array(12))
const box = await crypto.subtle.wrapKey(format, data, key, {
name: 'AES-GCM',
iv
})
return new SecretWrap(new Uint8Array(box), data.algorithm, data.usages, format, iv)
}
public async decrypt(key: CryptoKey): Promise<CryptoKey> {
log.trace('decrypt')
return crypto.subtle.unwrapKey(
this.type,
this.cipher,
key,
{
name: 'AES-GCM',
iv: this.iv
},
this.algorithm,
true,
this.usages
)
}
public toString(): string {
log.trace('toString')
return JSON.stringify({
cipher: a2b64(this.cipher),
iv: a2b64(this.iv),
algorithm: this.algorithm,
usages: this.usages,
type: this.type
})
}
public static fromString(data: string): SecretWrap | null {
log.trace('fromString')
const obj = this.parseJSON(data)
if (obj === null) return null
const cipher = b642a(obj.cipher)
if (cipher.is_err()) return null
const iv = b642a(obj.iv)
if (iv.is_err()) return null
return new SecretWrap(cipher.unwrap(), obj.algorithm, obj.usages, obj.type, iv.unwrap())
}
private static parseJSON(data: string): {cipher: string, iv: string, algorithm: KeyAlgorithm, usages: KeyUsage[], type: 'raw' | 'pkcs8'} | null {
log.trace('parseJSON')
try {
// TODO : Check the fields
return JSON.parse(data)
} catch (e) {
log.warn('Failed to parse JSON')
return null
}
}
}